Venetian blind ladder and like webbing



Dec. 25, 1956 G. F. FRENCH ETAL 2,775,255

VENETIAN BLIND LADDER AND LIKE WEBBI Filed Nov. 6, 1951 United StatesPatent '0 VENETIAN BLIND LADDER vAN D LIKE; WEBBING George FrederickFrench and Roger. French, Hale, England; Roger French, AlfredHanson, andNeville Christopher OBriemexecutors ofthe estate of GeorgeFred erickFrenchydeceased, assignors to said Roger French Application November 6,1951,. Serial N. 255,088...

Claims P y, pplication Great Britain November 7, 1950- 10.01am. (Cl..139384) This M invention. relates .to: Venetian. blind ladder and like.webbing of. theflkind comprising two :orzmore outer or main. bandings.between which are woven or;.partly wovemcross straps arrangediin .one ormore rows and in whichvthe cross straps .in anyone. row, or in laterallyoverlapping rows, are .of such length as to overlap longis tudinally i.e. in their length sohthatone. set oftwarps initiallycross.overnthroughanother. Suchoverlap may.

provide; the ,required overlap for the; blind: laths. 1

While such webbing is primarily known. and. used for Venetian blinds,-it has. other.uses', for. example, as a liningfonheadgear to hold. corkor like inserts between. the. .cross. straps, furniture, beds,upholstery, but for convenience such: webbing .will. be referred tohereinafter by the generic term. ladder webbing.

Examples .of ladder. webbing of .the kind above referred to aredescribed. .in our prior British. patent specification.

No. 512,835. particularly with reference. to. Figs. 11,12. and 13.Whilstsuchwebbing may easily be madevwith. the cross.strapsunwoven,certain problems arise; when such .cross straps..are. to be woven orpartly woven-due to the. combinedlongitudinal and lateral overlaps. For

example, inwa simple arrangement in whichthere are two sets of warpthreads for the cross straps (one SetvfOIT:

each alternate. cross strap) due. to. such combined overlap ,the warpsof one .sethaveto pass throughlithetwarps ofthe. other alternately inthe. length of each cross strap.

In consequence, .such .kind of ladder webbing has :so far. only been.made. with .unwoven or weftless cross strapsandthe present inventionhas for its. objectto providewan. improved ladder. webbing and method ofmaking qthe.

samewith woven .or :partly. woven cross straps.

The main object of i the. invention is to pprovide ladder Webbing of thetype described hereinbeforehaving. an.

improved character which enables..productio.n costs to befreduced. bysimplification. .of the weaving. process and increased loomspeed.

A- further object of thetinvention is .to providerladder webbing of.thetype describedhereinbefore which. whilst lighter and narrower thanknown types ofJadderWeb-p bing, maintains a. given tensile strength.

A still further object of the inventionis to provide such ladder.webbing .in .Which. the. whole-or only certainw parts of the. crossstraps .are woven and in which UIl'w woven warpsware-xdefined byadjacent. woven port-ions.

By buttonholes aremeant apertures throughwhich liftingcords or the likemay be passed.

These and many other objectsand advantages will be apparent from thefollowing descriptio-nwand claimss The invention will be describedfurther by Way of example with reference. to the accompanying drawingsin which:

Fig; 1 is a perspective view of one exampleofladder webbing. madeinaccordance with the present invention and having two main bands and asingle row of cross straps 'in line;

2.. Fig. 2 is a fragment-aryview. of a modification of the cross strapsshown in Fig.1;

Fig. 3 isa fragmentary .view of a. further modification of oneof thecross straps shown in Fig. l;

Fig. 4 is a perspective view showing a modification of Fig. 1;

Fig. 5 is a fragmentary view of a further modification of a cross strapmade in accordance with the invention; Fig. 6 is a perspective view ofastill further modified construction.

In one example of the invention as illustrated in Fig.

l ladder webbing having a singlelongitudinal row of cross. straps 11between main bandings 25, 26, formed. from two sets of warp threads andoverlapping in, their length, the webbing is woven -with..four shuttlesasfor theprevious ladder web, in which the two middle shuttles Weavethewarps of the staggered .two rows of .cross. straps, but with thisdifference that, when the crossing over of the strap warpsis effectedthe shuttle which has previouslybeen weaving aportion. of one cross:strap, is. nowused to weave a similar portion of the consecutive.

cross strap. Thus, from the point of such. cross. over,

each strap at one end is wovenwith weft 12 by one shut tie .and at theother end is woven. with weft 13 by the other of the twoshuttles-allocated for weavingthe cross straps.

in eachstrap 11 which will take any wear due to. the passage of thelifting cords as the blind. is .raised and lowered. Also, as has beenpreviously suggested, only some ofthe strap warp threadsmay be Woven theremainder 17 being weftless so that theablind laths maybe held betweenthe woven and unwoven warp threads and the lath held in position (Fig.4).

In a further. modification shown in Fig. 5, the shedding;

is effected to produce a button-hole 1i8.ir1.each cross strap 11. Thisis possible because, during the binding-in of the ends of one set ofwarps forthe. cross straps 11, both strap shuttles are rnade availablefor weaving thecentrebuttonhole portion 18 of the said cross strap 11.Thus, in any one cross strap the vweft 12 from one shuttle will becontinuous from .one. end and extend along one side-- of thebuttonrhole18, while the other side of .the-button-- hole 18 and theother endof the strap 11 will be woven..- by Weft 13'frorn theothershuttler The button-hole 18 can therefore bemade without increasingtheinumber of shuttles, i. e. still using only 4 shuttles and canextend;

for the combined ,length of the top and bottom binding in.

It will of course be appreciated that, in the buttonhole construction,while .both the intermediate shuttles are being used for weaving thetwohalves of the cross strap it will not be possible to use eitherof theseshuttles for the purpose ofstrengthening thebinding-in as is done inaccordance with our earlier British PatentNo. 453,832.

In all other examples it isequally to be appreciated that the use of thecross strap shuttles for strengthening the binding-in can be adopted.

The improved construction makes it possible to produce a narrower andlighterladder webbing yet having a broader and stronger. lath. strap byemploying more strap warp threads. Such improved webbing will be quickerand easier to manufactureandalso cheaper. The actualsheddingcanbesimplified to eliminatesomeofthe major.

Patented .Dec. 25, 1956 changes thus reducing the shock and requiringless skill and maintenance and enabling the loom speed to be increased.For a cross strap of previously determined tensile strength it ispossible to have wider cross strap with fewer picks which willconsequently give quicker production and cheaper cost and at the sametime retain its tensile strength. The partly woven, partly weftless formhas advantages over the weftless form described in our previous patentsin that the partly woven strap is enough to prevent the weftless strapwarp thread portion from spreading so as to be visible at the sides ofthe main bands. Thus, for example with the improved construction ofladder web narrower outer bandings can be used whilst the present strapweb width could be retained, or increased if necessary, thereby givingequal or greater purchasing power of the straps to the body Webs than inthe previously known constructions. Further, the laths are heldcentrally of the outer bandings.

With body webs 1" wide as against the present 1 /2 the cost of rawmaterials would be reduced by approximately one-third. Again, loomefliciency would be increased by the fact that approximately one-thirdmore running time would be provided for each weft package on thebandings or body webs. The method of lifting the strap warps may be suchthat heavy lifts (i. e. over three or four shuttles) could be eliminatedthereby allowing the loom to be run at a higher speed.

Instead of keeping the cross straps'of the same width as at presentwhich is substantially a practical maximum width, the said strap widthmay be increased and strengthened by the introduction of extra threadsgiving a resultant firmer binding-in and whilst an increase mayapparently have a disadvantage it does in fact leave a substantialadvantage in that the picks per inch could be reduced, enabling the rateof production to be increased whilst such cross straps would stillretain their former strength of binding-in to the outer bandings.Another constructional advantage where the cross straps are in alongitudinal line is not only that the warp tensions in the fabric arebalanced, but also the same amount of weft is drawn from the shuttles ateach pick, whereas with the staggered cross strap method this was notpossible, the weft being pulled off the shuttles unequally at each side.

In a further extension of the principle of the invention cross straps 11(see Fig. 6) need not be wholly in line but may overlap laterally to agreater or lesser degree.

What we claim is:

1. A ladder webbing comprising at least two outer main bandings and atleast one row of cross straps bound in at their ends between anyadjacent two main bandings, successive cross straps being of such lengththat in-line portions thereof overlap longitudinally, so that one set ofwarp threads initially cross over through another set, successive crossstraps each having portions at least thereof relative to and between itsbound-in ends woven, one portion with picks of one common weft threadand another portion with picks of a difierent common weft thread.

2. A ladder webbing comprising at least two outer main bandings and atleast one row of cross straps bound in at their ends between anyadjacent two main bandings, successive cross straps being formedalternately from two sets of warp threads and being of such length thatin-line portions thereof overlap longitudinally, so that one set of warpthreads initially cross over through another set, successive crossstraps each having portions at least thereof relative to and between itsbound-in ends woven, one portion with picks of one common weft threadand another portion with picks of a different common weft thread.

3. A ladder webbing comprising at least two outer main bandings and atleast one row of cross straps bound in at their ends between anyadjacent two main bandings, successive cross straps being of such lengththat in-line portions thereof overlap longitudinally, so that one set'ofwarp threads initially cross over through another set, each successivecross strap being at least partially woven with picks of at least twodifferent common wef threads.

4. A ladder webbing comprising at least two outer main bandings and atleast one row of cross straps bound in at their ends between anyadjacent two main bandings, successive cross straps being of such lengththat in-line portions thereof overlap longitudinally, so that one set ofwarp threads initially cross over through another set, successive crossstraps each having like portions at least thereof relative to andbetween its bound-in ends woven, one portion with picks of one commonweft thread and another portion with picks of a different common weftthread.

5. A ladder webbing comprising at least two outer main bandings and atleast one row of cross straps bound in at their ends between anyadjacent two main bandings, successive cross straps being of such lengththat in-line portions thereof overlap longitudinally, so that one set ofwarp threads initially cross over through another set, successive crossstraps each having at least two diflferent portions woven between itsbound-in ends, one portion of each cross strap being like one portion ofeach other cross strap and all such like portions being woven with picksof one common weft thread, another portion of each cross strap beinglike another portion of each other cross strap and all such other likeportions being woven with picks of a difierent common weft thread.

6. A ladder webbing comprising at least two outer main bandings and atleast one row of cross straps bound in at their ends between anyadjacent two main bandings, successive cross straps being of such lengththat in-line portions thereof overlap longitudinally, so that one set ofwarp threads initially cross over through another set, the same part,relative to and between its bound-in ends, of each successive crossstrap being woven with picks of one common Weft thread and anothercorresponding part be tween the bound-in ends of each successive crossstrap being woven with picks of a diiferent common weft thread, said twoparts defining on each cross strap a portion of unwoven warp threadsthrough which lifting cords may be passed. p

7. A ladder webbing comprising at least two outer main bandings and atleast one row of cross straps bound in at their ends between anyadjacent two main bandings, successive cross straps being of such lengththat in-line portions thereof overlap longitudinally, so that one set ofwarp threads initially cross over through another set, correspondinghalves, relative totheir bound-in ends, of each cross strap being wovenwith picks of one common weft thread and the other halves with picks ofa second and difierent common weft thread.

8. A ladder webbing comprising at least two outer main bandings and atleast one row of cross straps bound in at their ends between anyadjacent two main bandings, successive cross straps being of such lengththat in-line portions thereof overlap longitudinally, so that one set ofwarp threads initially cross over through another set, the same part,relative to and between its bound in ends and being less than halfthereof, of each successive cross strap being woven with picks of onecommon weft thread, and another corresponding part of each successivecross strap between its bound-in ends and being also less than halfthereof, being woven with picks of a second and different common weftthread, said two parts defining on each cross strap a portion of'unwoven warp threads successive cross straps in each row beingstaggeredtransversely but having in-line portions thereof overlappinglongitudinally, so that one set of Warp threads cross over and at leastpartially through another set, successive cross straps each havingportions at least thereof relative to and between its bound-in endswoven, one portion with picks of one common weft thread and anotherportion with picks of a difierent common weft thread.

References Cited in the file of this patent UNITED STATES PATENTS Re.22,925 Rasero Oct. 7, 1947 6 French Apr. 25, 1939 French Apr. 25, 1939French Apr. 15, 1941 FOREIGN PATENTS Great Britain Oct. 4, 1940

